Suede type artificial leather with antifouling property and preparation method therefor

ABSTRACT

A suede type artificial leather having an antifouling property is provided. A polymeric elastomer is impregnated in a nonwoven fabric formed by three-dimensionally interlacing ultrafine fibers and raising is formed, wherein the polymeric elastomer is a fluorine-containing modified polyurethane, and the fluorine-containing modified polyurethane is obtained by a polymerization of a urethane prepolymer having isocyanate groups at terminals, obtained by reacting a diol and a diisocyanate, and a fluorinated carbon compound having hydroxy functional groups at both terminals. The fluorine-containing modified polyurethane has a weight average molecular weight of 500,000 to 800,000. The suede type artificial leather is prepared by using the fluorine-containing polyurethane elastomer.

TECHNICAL FIELD

The present invention relates to a suede type artificial leather havingantifouling properties, and more particularly to a simple method ofpreparing an artificial leather impregnated with a modified polyurethanehaving an antifouling property, which the addition of an additive havingan antifouling function is not needful.

BACKGROUND ART

Artificial leather is prepared by impregnating a polymer elastomer in anonwoven fabric formed by three-dimensionally interlacing ultrafinefibers. The artificial leather has a smooth texture and uniqueappearance which is similar to natural leather and is widely used invarious fields such as shoes, clothes, gloves, miscellaneous goods,furniture and automobile interior materials.

Artificial leather requires various characteristics according to itsuse. For example, the properties required for artificial leather forclothing include high durability, high sensitivity, excellent dyeabilitywhich can be stained with various colors and concentrations and highfastness.

In order to improve the durability among these demand characteristics,artificial leather is required to be provided with an antifoulingfunction including a water-repellent and oil-repellent function forinhibiting the occurrence of fouling even after a long-term use.

To provide an antifouling property to artificial leather, afluorine-based or silicone-based surfactant can be mixed withpolyurethane and a mixture can be impregnated in a nonwoven fabric,thereby arranging a fluorine chain or a silicone chain on the surface ofthe artificial leather. The occurrence of fouling can be suppressed fromthe outside of the artificial leather accordingly.

However, fluorine-based or silicone-based surfactants are generallyinactive additives, and in case that they are mixed with polyurethane,there is a problem that they are not chemically bonded to each other,thus they are free to move in the urethane molecular structure and as aresult, transition of the surfactants to the surface of artificialleather occurs causing a surface change with the passage of timethereof.

Korean Patent No. 0969839 discloses a modified urethane to whichfluorine is bonded and a method of preparing leathery sheet object usingthe modified urethane without the addition of a fluorine-based compound.According to the patent, a urethane compound modified withfluorine-containing side chain in which

(i) 3 to 12 fluorine-containing side chains having a molecular weight of200 to 1,000 are bonded to a urethane bond-containing compound having amolecular weight of 500 to 5,000

(ii) the fluorine content is 20 to 60 weight % in terms of fluorineatoms, and

(iii) containing 6 to 36 urethane bonds per a molecule,

improves water repellency and water resistance at the cut cross sectionof the leathery sheet object, are disclosed.

However, according to the patent, the urethane compound modified withfluorine-containing side chain is used together with polyurethane whichis an elastomer constituting the treatment liquid of a leathery sheetobject, and exhibits an effect as a water-repellent agent as anadditive.

On the other hand, the development of providing an antifouling effect byan elastomer impregnated in artificial leather without adding anantifouling additive is progressing.

Disclosure Technical Problem

To solve the above problems, an object of the present invention is toprovide artificial leather impregnated with a novel modifiedpolyurethane, having an antifouling property without adding an additivehaving an antifouling property.

Technical Solution

To achieve the object of the present invention, an aspect of the presentinvention provides a suede type artificial leather having antifoulingproperty in which a polymeric elastomer is impregnated in a nonwovenfabric formed by three-dimensionally interlacing ultrafine fibers andraising is formed, wherein the polymeric elastomer is afluorine-containing modified polyurethane, and the fluorine-containingmodified polyurethane is a product obtained by a polymerization reactionbetween a urethane prepolymer having isocyanate groups at terminals,obtained by reacting a diol and a diisocyanate, and a fluorinated carboncompound having hydroxy functional groups at both terminals, and has aweight average molecular weight (Mw) of 500,000 to 800,000.

The present invention also provides a method of preparing a suede typeartificial leather having antifouling property in which a polymericelastomer is impregnated in a nonwoven fabric formed bythree-dimensionally interlacing ultrafine fibers and raising is formed,wherein the polymeric elastomer is a fluorine-containing modifiedpolyurethane, and the fluorine-containing modified polyurethane isprepared by a method comprising: preparing a urethane prepolymer havinga weight average molecular weight (Mw) of 400,000 to 700,000 by reactinga diol and a diisocyanate; and preparing a polymerization product havinga weight average molecular weight (Mw) of 500,000 to 800,000 by reactingthe prepolymer and a fluorinated carbon compound having hydroxyfunctional groups at both terminals.

Advantageous Effects

According to the present invention, artificial leather impregnated witha fluorine-containing modified polyurethane elastomer having antifoulingproperty also exhibits excellent water repellency in addition to theantifouling property.

In addition, the artificial leather of the present invention candecrease the surface change with the passage of time, as compared withartificial leather produced by separately adding a fluorine-containingsurfactant having the large occurrence of surface change with thepassage of time due to the migration of the surfactant.

Further, since the separate addition of the fluorine-based surfactant isnot required, the manufacture method can be simplified.

DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a polymerization reaction scheme of afluorine-containing modified polyurethane according to an embodiment ofthe present invention.

FIG. 2 shows a drawing of an apparatus for evaluating water repellencyof the artificial leather.

FIG. 3 is a rating criterion for the water repellency evaluation.

BEST MODE

The present invention relates to a suede type artificial leather havingantifouling property in which a polymeric elastomer is impregnated in anonwoven fabric formed by three-dimensionally interlacing ultrafinefibers and raising is formed, wherein the polymeric elastomer is afluorine-containing modified polyurethane.

The fluorine-containing modified polyurethane is a product obtained by apolymerization reaction between a urethane prepolymer having isocyanategroups at terminals and a weight average molecular weight (Mw) of400,000 to 700,000, obtained by reacting a diol and a diisocyanate, anda fluorinated carbon compound having hydroxy functional groups at bothterminals, and has a weight average molecular weight (Mw) of 500,000 to800,000.

The diol may be used alone or in combination with diols such as1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, ethylene glycol,diethylene glycol, polyethylene glycol, polypropylene glycol orpolytetramethylene glycol.

The diisocyanate may be 1,4-tetramethylene diisocyanate,1,6-hexamethylene diisocyanate, 1,12-dodecamethylene diisocyanate,cyclohexane-1,3- to 1,4-diisocyanate,1-isocyanate-3-isocyanatemethyl-3,5,5-trimethylcyclohexane(isophoronediisocyanate), bis-(4-isocyanatecyclohexyl) methane(hydrogenated MDI),2- to 4-isocyanatecyclohexyl-2-isocyanatecyclohexylmethane, 1,3- to1,4-tetramethylxylene diisocyanate, 2,4- to 2,6-diisocyanate toluene,2,2-2,4- to 4,4′-diphenylmethane diisocyanate , 1,5-naphthalenediisocyanate, xylene diisocyanate or diphenyl-4,4-diisocyanate, and thelike, but are not limited thereto.

In the present invention, when the diol is reacted with thediisocyanate, the proportion to be reacted needs an excess amount of allNCO groups rather than all OH groups. By adjusting the ratio of the dioland the diisocyanate to react as such, the resulting urethane prepolymermay have an isocyanate group terminal in side chains thereof.

At this time, the molar ratio of the diol and the diisocyanate ispreferably 1:1.2 to 1:1.4 because the fluorine-containing modifiedpolyurethane having the weight average molecular weight range of thepresent invention can be produced.

When the molar ratio is less than 1:1.2, a side reaction occurs due tomoisture or active hydrogen, etc. in the air, or the isocyanate reactswith each other to manifest a property of isocyanate for forming atrimer and to decrease the polymerization efficiency due to the increaseof inactive NCO. When the molar ratio is more than 1:1.4, the excess ofNCO groups causes an insufficient OH group so that it is difficult toraise the degree of polymerization.

In order to ensure the mechanical properties required in case that thefluorine-containing modified polyurethane of the present invention isapplied to artificial leather, it is necessary to increase thepolymerization molecular weight to an appropriate level easily and to doso, a urethane prepolymer can be prepared first.

If the weight average molecular weight (Mw) of the urethane prepolymeris less than 400,000, the molecular weight of the fluorine-containingmodified polyurethane is lowered, and the mechanical properties such astear strength, etc. and the chemical properties such as thermalstability and hydrolysis resistance, etc. are lowered. If it exceeds700,000, the gelation phenomenon may occur in the production of thefluorine-containing modified polyurethane, and the viscosity of thefluorine-containing modified polyurethane may be high to reduce theworkability in blending of an elastomer impregnation solution, and theresulting fluorine-containing modified polyurethane may be hardened,which may deteriorate the sensual quality in artificial leather.

The fluorinated carbon compound having hydroxy functional groups at bothterminals is represented by the following Chemical Formula 1, has 8 to14 fluorine groups bonded to one side chain and fluorine content of 50to 70 mol % in one functional group and is an ether diol having hydroxyfunctional groups at both terminals.

HO—CH₂—CF₂—O—(CF₂CF₂O) m-(CF₂O) n-CF₂—CH₂—OH   [Chemical Formula 1]

The fluorine-containing modified polyurethane obtained by reacting theether diol of the Chemical Formula 1 with the urethane prepolymer canprovide water-repellent and oil-repellent functions because the fluorinewhich is present as the diatomic molecule in the element state, in theside chain of the urethane polymer is bonded to prevent that themodified polyurethane is bonded to other atoms or molecules. Thus, bythe fluorine-containing modified polyurethane of the present invention,the artificial leather can be suppressed deposition of an externalcontaminant and easily removed contaminants on the coated surface.

A commercialized product of a fluorinated carbon compound having hydroxyfunctional groups at both terminals is Solvay's FLUOROLINK.

The polymerization of the fluorine-containing modified polyurethane ofthe present invention can be carried out through theaddition-polymerization by adding dropwise the fluorinated carboncompound having hydroxy functional groups at both terminals to theurethane prepolymer until the desirable molecular weight is reached. Atthis time, the addition amount of the fluorinated carbon compoundcorresponds to the moles of excess isocyanate in preparing the urethaneprepolymer.

When a fluorinated carbon compound having hydroxy functional groups atboth terminals is added at a time, the fluorinated carbon compound ispartially bound to the urethane prepolymer, so that the dispersion ofthe fluorine groups in the fluorine-containing modified polyurethanebecomes insufficient and as a result it is difficult to develop theuniform antifouling performance. Therefore, it is preferable to slowlyadd dropwise.

The fluorine-containing modified polyurethane of the present inventionis polymerized by the above-mentioned method and is characterized byhaving a weight average molecular weight (Mw) of 500,000 to 800,000. Ifthe weight average molecular weight (Mw) is less than 500,000, themechanical strength such as tear strength, etc. and chemical propertiessuch as thermal stability, hydrolysis resistance, and the like inartificial leather may be reduced. When the weight average molecularweight (Mw) is more than 800,000, the viscosity of thefluorine-containing modified polyurethane may be high to reduce theworkability in blending of an elastomer impregnation solution, and theresulting fluorine-containing modified polyurethane may be hardened,which may deteriorate the sensual quality in artificial leather.

It is preferable that the fluorine-containing modified polyurethane ofthe present invention has a fluorine content of 5 to 20mol %. When thecontent is less than 5 mol %, the antifouling performance isinsufficient, and when the content is more than 20 mol %, the waterrepellency is too strong so that the fluorine-containing modifiedpolyurethane cannot undergo the substitution solidification in themanufacturing process of the artificial leather.

An example of the synthesis reaction of the fluorine-containing modifiedpolyurethane described above can be represented by the followingreaction:

Here, R and R′ are each independently an alkyl group.

Generally, artificial leather can be prepared by immersing a nonwovenfabric formed by three-dimensionally interlacing ultrafine fibers in animpregnating liquid comprising a polymeric elastomer such aspolyurethane, impregnating the polymeric elastomer to solidify theelastomer in the nonwoven fabric, raising by grinding and dyeing.

In the present invention, the fluorine-containing modified polyurethaneof the present invention can be used as a polymeric elastomer of theimpregnating liquid. The fluorine-containing modified polyurethane maybe used as an impregnating liquid by diluting it in dimethyl formamideof 100 to 200 wt % in respect of the weight of the fluorine-containingmodified polyurethane.

The present invention will be described more fully hereinafter withreference to the accompanying drawings, in which exemplary embodimentsof the invention are shown.

PREPARATION EXAMPLE 1

Polytetramethylene glycol (Mw: 1,500-2,500) of 0.45 mol, ethylene glycolof 0.47 mol and 1,4-butanediol of 0.08 mol were subjected to additionpolymerization with 1.2 mol of 4,4′-diphenylmethane diisocyanate, andthe produced polymerization product was diluted and dissolved indimethylformamide so as to be a total solid content of 40% by weight toprepare an NCO-terminated polyurethane prepolymer having a weightaverage molecular weight (Mw) of 700,000.

The prepared prepolymer was subjected to addition polymerization with0.2 mol of a fluorinated carbon compound having hydroxy functionalgroups at both terminals in a side chain (trade name: FLUOROLINK D10-H,manufactured by Solvay, Mw: 1,400) and the produced polymerizationproduct was diluted and dissolved in dimethylformamide so as to be atotal solid content of 30% by weight to prepare a fluorine-containingmodified polyurethane having a weight average molecular weight (Mw) of800,000.

PREPARATION EXAMPLE 2

Polytetramethylene glycol (Mw: 1,500-2,500) of 0.45 mol, ethylene glycolof 0.47 mol and 1,4-butanediol of 0.08 mol were subjected to additionpolymerization with 1.3 mol of 4,4′-diphenylmethane diisocyanate, andthe produced polymerization product was diluted and dissolved indimethylformamide so as to be a total solid content of 40% by weight toprepare an NCO-terminated polyurethane prepolymer having a weightaverage molecular weight (Mw) of 600,000.

The prepared prepolymer was subjected to addition polymerization with0.3 mol of a fluorinated carbon compound having hydroxy functionalgroups at both terminals in a side chain (trade name: FLUOROLINK D10-H,manufactured by Solvay, Mw: 1,400) and the produced polymerizationproduct was diluted and dissolved in dimethylformamide so as to be atotal solid content of 30% by weight to prepare a fluorine-containingmodified polyurethane having a weight average molecular weight (Mw) of700,000.

PREPARATION EXAMPLE 3

Polytetramethylene glycol (Mw: 1,500-2,500) of 0.45 mol, ethylene glycolof 0.47 mol and 1,4-butanediol of 0.08 mol were subjected to additionpolymerization with 1.4 mol of 4,4′-diphenylmethane diisocyanate, andthe produced polymerization product was diluted and dissolved indimethylformamide so as to be a total solid content of 40% by weight toprepare an NCO-terminated polyurethane prepolymer having a weightaverage molecular weight (Mw) of 400,000.

The prepared prepolymer was subjected to addition polymerization with0.4 mol of a fluorinated carbon compound having hydroxy functionalgroups at both terminals in a side chain and the produced polymerizationproduct was diluted and dissolved in dimethylformamide so as to be atotal solid content of 30% by weight to prepare a fluorine-containingmodified polyurethane having a weight average molecular weight (Mw) of500,000.

PREPARATION EXAMPLE 4

Polytetramethylene glycol (Mw: 1,500-2,500) of 0.45 mol, ethylene glycolof 0.47 mol and 1,4-butanediol of 0.08 mol were subjected to additionpolymerization with 1.0 mol of 4,4′-diphenylmethane diisocyanate, andthe produced polymerization product was diluted and dissolved indimethylformamide so as to be a total solid content of 70% by weight toprepare a reaction-terminated polyurethane having a weight averagemolecular weight (Mw) of 700,000.

PREPARATION EXAMPLE 5

Polytetramethylene glycol (Mw: 1,500-2,500) of 0.45 mol, ethylene glycolof 0.47 mol and 1,4-butanediol of 0.08 mol were subjected to additionpolymerization with 1.7 mol of 4,4′-diphenylmethane diisocyanate, andthe produced polymerization product was diluted and dissolved indimethylformamide so as to be a total solid content of 40% by weight toprepare an NCO-terminated polyurethane prepolymer having a weightaverage molecular weight (Mw) of 350,000.

The prepared prepolymer was subjected to addition polymerization with0.7 mol of a fluorinated carbon compound having hydroxy functionalgroups at both terminals in a side chain and the produced polymerizationproduct was diluted and dissolved in dimethylformamide so as to be atotal solid content of 30% by weight to prepare a fluorine-containingmodified polyurethane having a weight average molecular weight (Mw) of450,000.

PREPARATION EXAMPLE 6

Polytetramethylene glycol (Mw: 1,500-2,500) of 0.45 mol, ethylene glycolof 0.47 mol and 1,4-butanediol of 0.08 mol were subjected to additionpolymerization with 1.0 mol of 4,4′-diphenylmethane diisocyanate, andthe produced polymerization product was diluted and dissolved indimethylformamide so as to be a total solid content of 70% by weight toprepare a reaction-terminated polyurethane having a weight averagemolecular weight (Mw) of 700,000.

EXAMPLE 1

The fluorine-containing modified polyurethane of the Preparation Example1 was diluted with 150% by weight of dimethylformamide in respect of theweight of the polyurethane to prepare an impregnating liquid.

The nonwoven fabric in which the polyester fibers (0.3 denier, fiberlength: 51 mm) was entangled was immersed in the impregnation solution,taken out and carried out coagulating process in an aqueous solutiondiluted with 20% by weight of dimethylformamide to form thefluorine-containing modified polyurethane elastomer impregnated nonwovenfabric in which a fine porous layer was formed in the fiber structure.

Thereafter, a suede type artificial leather was produced by raisingfinishing on the surface of the elastomer impregnated nonwoven fabric.

EXAMPLE 2

A suede type artificial leather was produced in the same manner as inExample 1, except that the fluorine-containing modified polyurethane ofPreparation Example 2 was used to prepare an impregnation solution.

EXAMPLE 3

A suede type artificial leather was produced in the same manner as inExample 1, except that the fluorine-containing modified polyurethane ofPreparation Example 3 was used to prepare an impregnation solution.

COMPARATIVE EXAMPLE 1

A suede type artificial leather was produced in the same manner as inExample 1, except that the fluorine-containing modified polyurethane ofPreparation Example 4 was used to prepare an impregnation solution.

COMPARATIVE EXAMPLE 2

A suede type artificial leather was produced in the same manner as inExample 1, except that the fluorine-containing modified polyurethane ofPreparation Example 5 was used to prepare an impregnation solution.

COMPARATIVE EXAMPLE 3

A suede type artificial leather was produced in the same manner as inExample 1, except that the reaction-terminated polyurethane ofPreparation Example 6 is diluted with a mixture of 150% by weight ofdimethylformamide and 0.5% of a fluorine-based surfactant (trade nameFC-4430, 3M) with respect of the weight of the polyurethane, to preparean impregnation solution.

The weight average molecular weights (Mw) of the polymer prepared in theabove Examples and Comparative Examples were measured using gelpermeation chromatography (GPC) (RI-8000, manufactured by TosohCorporation) passing through the column connected TSKgel super HM-L,TSKgel super HM-M and TSKgel super HM-N (tosoh) in series withtetrahydrofuran (flow rate: 1 mL/min) as a mobile phase and the columnoven at temperature of 40° C.

The raw material composition ratio for the polymerization in the abovePreparation Examples and the weight average molecular weight of thepolymerization product are shown in the following Table 1.

TABLE 1 Preparation Preparation Preparation Preparation PreparationPreparation Example 1 Example 2 Example 3 Example 4 Example 5 Example 6diol   1 mol   1 mol   1 mol 1 mol   1 mol 1 mol Diisocyanate 1.2 mol1.3 mol 1.4 mol 1 mol 1.7 mol 1 mol prepolymer 700,000 600,000 400,000700,000 350,000 700,000 FLUOROLINK 0.2 mol 0.3 mol 0.4 mol — 0.7 mol —D10-H Fluorine- 800,000 700,000 500,000 — 450,000 — containing modifiedpolyurethane surfactant — — — — — 0.5% (FC-4430) The value of thesurfactant is that in elastomer impregnation solution.

The properties of the artificial leather prepared in the above Examplesand Comparative Examples were evaluated according to the followingantifouling property evaluation method, and the results are shown inTable 2 below.

Evaluation Method of Antifouling Property

An artificial leather sample was cut into a size of 5×15 cm and placedin a rubbing fastness tester (model name DL-2007) and a test fabric(product name: IEC carbon black/mineral oil, manufactured by EMPA) wasplaced on the surface of the fouled sample and rubbed by 10 timesreciprocating motion, and the fouled sample was visually compared togive a fouling degree.

(Standard of fouling grade,

5: no visible fouling, 4: slightly visible but almost inconspicuousfouling, 3: slightly fouled and visible, 2: slightly severe fouling, 1:significant fouling)

Water Repellency Evaluation Method

The artificial leather sample was fixed (diameter 10 cm) as shown inFIG. 2 and then tilted at an angle of 45°. Then, 100 ml of water wasinjected into the spray-type funnel located at the upper part, and thedegree of distribution of the water droplets on the surface of thesample after the completion of the spraying was observed to give arating according to FIG. 3.

TABLE 2 Comparative Comparative Comparative Example 1 Example 2 Example3 Example 1 Example 2 Example 3 Fouling 3.5 3.5 3.5 2.0 2.5 3.5 gradeWater 3.5 4.0 4.5 2.5 3.0 2.5 repellency rating

As shown in the above Table 2, it can be confirmed that, the artificialleather of the Example according to the present invention, in which thefluorine-containing modified polyurethane is impregnated as an elastomerhas the same antifouling performance as the artificial leather(Comparative Example 3) in which the fluorine-containing surfactant wasseparately added, and exhibits improved water repellency at the sametime.

The artificial leather according to the present invention is anartificial leather in which a fluorine-containing modified polyurethanehaving an antifouling property is impregnated. The fluorine-containingsurfactant does not need separately for the antifouling property duringthe production of artificial leather so that productivity increase ispossible. The artificial leather according to the present inventionexhibits an excellent antifouling performance that suppresses thesurface change with the passage of time of the artificial leather causedby using a fluorine-containing surfactant, thereby improving theappearance quality of the artificial leather.

Although the present invention has been described in detail withreference to the specific features, it will be apparent to those skilledin the art that this description is only for a preferred embodiment anddoes not limit the scope of the present invention. Thus, the substantialscope of the present invention will be defined by the appended claimsand equivalents thereof.

1. A suede type artificial leather having antifouling property in whicha polymeric elastomer is impregnated in a nonwoven fabric formed bythree-dimensionally interlacing ultrafine fibers and raising is formed,wherein the polymeric elastomer is a fluorine-containing modifiedpolyurethane, and the fluorine-containing modified polyurethane is aproduct obtained by a polymerization reaction between a urethaneprepolymer having isocyanate groups at terminals, obtained by reacting adiol and a diisocyanate, and a fluorinated carbon compound havinghydroxy functional groups at both terminals, and has a weight averagemolecular weight (Mw) of 500,000 to 800,000.
 2. The suede typeartificial leather having antifouling property according to claim 1,wherein the urethane prepolymer has a weight average molecular weight(Mw) of 400,000 to 700,000.
 3. The suede type artificial leather havingantifouling property according to claim 1, wherein the fluorinatedcarbon compound having hydroxy functional groups at both terminals, has8 to 14 fluorine groups bonded to one side chain and fluorine content of50 to 70 mol % in one functional group and is an ether diol havinghydroxy functional groups at both terminals.
 4. A method of preparing asuede type artificial leather having antifouling property in which apolymeric elastomer is impregnated in a nonwoven fabric formed bythree-dimensionally interlacing ultrafine fibers and raising is formed,wherein the polymeric elastomer is a fluorine-containing modifiedpolyurethane, and the fluorine-containing modified polyurethane isprepared by a method comprising: preparing a urethane prepolymer havinga weight average molecular weight (Mw) of 400,000 to 700,000 by reactinga diol and a diisocyanate; and preparing a polymerization product havinga weight average molecular weight (Mw) of 500,000 to 800,000 by reactingthe prepolymer and a fluorinated carbon compound having hydroxyfunctional groups at both terminals.
 5. The method of preparing a suedetype artificial leather according to claim 4, wherein the diol and thediisocyanate is reacted at a molar ratio of 1:1.2 to 1:1.4 to preparethe urethane prepolymer.
 6. The method of preparing a suede typeartificial leather according to claim 4, wherein the fluorinated carboncompound having hydroxy functional groups at both terminals, has 8 to 14fluorine groups bonded to one side chain and fluorine content of 50 to70 mol % in one functional group and is an ether diol having hydroxyfunctional groups at both terminals.